Piezoelectric materials are used for a number of applications. For example, piezoelectric materials may be used in actuators to achieve precise positioning in response to an applied electrical signal. Such applications may be used in devices such as disk drives. Multilayered piezoelectric/conductor stacks are of interest because of their higher piezoelectric response per volt than single layer piezoelectric devices. In other words, a piezoelectric multilayer has a higher displacement and force per volt than a single layer piezoelectric having a comparable thickness. FIG. 1 depicts such a conventional piezoelectric multilayer 10. For simplicity, only portions of the conventional piezoelectric multilayer 10 are shown. The conventional piezoelectric multilayer 10 is formed on a substrate 10 and includes piezoelectric material 20 and conventional conductive structures 30 and 40. The piezoelectric material 20 is actually composed of layers 22. Each conventional conductive structure 30 and 40 includes conductive plates 32 and 42, respectively. The conductive plates 32 are interleaved with the conductive plates 42. In other words, conductive plates 32 alternate with conductive plates 42 as the piezoelectric material 20 is traversed vertically in FIG. 1. The conventional conductive structures 30 and 40, and thus conductive plates 32 and 42, respectively, are electrically isolated. The conductive plates 32 and 42 are also spaced apart by a distance, d. Generally d, or the thickness of a piezoelectric layer 22, is constant through the piezoelectric material 20. Typically, d is greater than one micron.
In operation, the conventional conductive structures 30 and 40 are typically held at differing potentials, V+ and V−. As a result, each layer 22 of the piezoelectric material 20 is subject to the same electric field that alternates in direction between the layers 22. As a result of the potential difference between the conductive plates 32 and 42, a response is induced in the layers 22 of the piezoelectric material 20.
Various methods may be employed to fabricate the conventional piezoelectric multilayer 10. For example, the piezoelectric material 20 may be composed of layers which are defined using a thick film method. Alternatively, bulk sheets of piezoelectric may be laminated. Connection may be made to the conductive plates 32 and 42 through vias (not explicitly shown in FIG. 1) that are etched in the bulk piezoelectric material 20, and then refilled. Such conventional piezoelectric multilayers 10 are generally on the order of tens of microns thick, or greater.
Although the conventional piezoelectric multilayer 10 may be fabricated, other mechanisms for forming the multilayer 10 are desired. For example, the ability to obtain the desired geometry and thus voltage levels of the conventional piezoelectric multilayer 10 may be limited when using conventional fabrication methods. Accordingly, what is needed is an improved method for fabricating a piezoelectric multilayer.